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Green Building

Martin Holladay features this home in the February issue of Energy Design Update. Apparently the Denver Habitat for Humanity built one and found it's a net producer of energy.

Martin says the energy effciency and renewable energy features add about $42,000 to the cost of the 1200 sf home, but PV incentives brought that figure down to $28,000. I'm curious what it cost to build. Do you know Martin?

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Local H4H's around the country are doing some amazing work around affordable, green, super-efficient houses.

I'm involved in our chapter's first green build project - we're not as ambitious as Austin (I think they've been in the forefront on this for a while) but it should be cool nonetheless - we're applying for LEED certification.

Speaking of which, it's a great volunteer opportunity - in addition to the good work, and helping provide affordable housing, I've met some interesting people with similar passions. On a purely mercenary level, it's been great networking. Which is obviously not the point, but it's a good perk.

And Bill, I agree with you. Why are energy efficiency upgrades the only things we apply this strict calculus to?

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Patrick,
More details about the house, a simple rectangular 1,200-square-foot ranch, can be found in the June 2006 issue of Energy Design Update. Since almost all labor in a Habitat for Humanity house is donated, cost figures are difficult to calculate. It is safe to say, however, that the design is simple, basic, and inexpensive -- except for the energy-efficiency features.
George Roberts is correct that the cost of the photovoltaic array cannot be justified by simple economics. PV power is expensive power, and a grid-connected homeowner who invests in a PV array is choosing to buy expensive electricity. Of course, many states have subsidies that transfer some of the cost of this expensive electricity to the general rate-paying public.
Other elements of the Habitat for Humanity house in question -- superinsulated walls, thick attic insulation, passive solar orientation, orientation-specific glazing, and a solar hot water system -- are relatively inexpensive and show a much more favorable return on investment that the photovoltaic array.
The bottom line: anyone interested in investing in energy-efficiency improvements in order to lower energy costs should mimic the design of a so-called zero-energy house in most respects, but skip the photovoltaic array. The cheapest path does not include PV.
Other factors not mentioned in this analysis: electricity may get more expensive in the future, improving the payback for PV; PV modules may get cheaper in the future; and saving the planet is a good thing, even when it is more expensive than trashing the planet.

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I think your response is fairly typical George--how sad. I'm guessing that someday the prevailing attitudes in this country will change, but for now the only thing that motivates some people to conserve energy is saving money. It's the same attitude that says biodiversity is important because their might be economic gain in some plant or animal that we don't yet know about. I call this "the cure for cancer" argument.

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Patrick,
While I respect your viewpoint, Patrick, and I know your heart is in the right place, I urge you not to be so quick to judge George. Cost-effectiveness considerations are an important guide to deciding which energy efficiency measures are worth pursuing first. And there are already signs that photovoltaic subsidies are leading to strange energy efficiency investments. For example, when PV arrays are highly subsidized, they tend to get installed in upper middle class homes that may be relatively inefficient. (In at least one case, a California home with electric resistance heat installed a PV array on the roof, because of all the subsidies.) Before investing in so many PV arrays, we should first be investing in more insulation, better windows, and air-tightening measures -- and if we want to be investing in subsidies, these should be designed, of course, to first help our poorest neighbors. There is nothing wrong with calculating whether a large investment in "green" technology makes economic sense.

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Martin - I haven't read your piece but are all the "additional costs" due to the PV array? I've looked at the Austin project but not that closely at the numbers. Your larger point is of course correct - energy efficiency can turn into an excuse to just consume more (or the same amount, but cheaper) - like buying a Prius but then driving twice as much because you're using gas so efficiently.

In this instance, as well, it's frequently hard to quantify costs - I wouldn't be surprised if the PV array was donated in part or in full. On the project I'm working on, it's part of the challenge - it's easy to build cheaply if everyone wants to donate time and materials, but if you're trying to demonstrate that it can be done by everyone, it's a different story. I in fact argued against a PV or Hot Water array on the Habitat house we're designing for precisely those reasons - I'd rather focus on super-insulation, IAQ, durable materials, siting, etc.

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Amen Martin. Air sealing and weatherization will always provide a bigger bang for the buck than PVs, but I'm encouraged that somebody (Denver HFH) has built a zero-energy energy house that's not a rich person's feel-good hobby like you describe. Really, I understand the point George is making and maybe I was unfairly judging him.

I know I should give George some latitude. As an engineeer he's trained to see things in terms of cost versus benefit. Me, I think things are a little less black and white.

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I make financial decisions based on what my investment opportunities are. I get 20% return on investing in my business so I expect 20% on investing in energy conservation.

As for my house. I buy or rent based on economics also. Currently my wife's business and my business are run out of our house. We save $3000/month over having off site business. That is more than a 20% return on housing capital.

patrick ---

Energy use appears to be important to you ...

I am all in favor of high taxes on traditional energy sources - coal, oil and such. $10/gallon tax on gas is fine with me.

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George wants a 20% payback on the "investment." Exclusive to energy issues.

Your most compelling case against PV is for running electric resistant heat. How common is that?

How can you justify granite and barrel tile roofs over HPL and three-tab?
Because that is probably what is in the market.

It is already happening that green, whatever that means, and energy efficient are appearing as preferred homes and will sell and resell better.
Then there is the issue that many homeowners would "enjoy" a PV powered home.
Energy costs WILL go up. Before the '73 oil embargo it was being said that nuclear power would be so cheap to produce it would not be worth metering.
How much of that have we seen?
While PV is out of the reach of many I am not clear why some are so adamantly against it.
When you say it is not cost effective, and that is repeated enough, people will begin to believe it is not a useful solution.
That is a shame.
Yours and George's arguments do not convince me. What else do you have?

While I do not currently sell or install PV products I have in the past and believe in the technology.
Bill R

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Dan,
The Habitat for Humanity house in Wheat Ridge, Colorado had the following incremental measures for improved performance:
Photovoltaic array: $29,000 unsubsidized cost ($15,000 subsidized cost).
Other measures (extra insulation, better windows, solar thermal system): $13,000.
Bill,
I'm not telling you there's anything wrong with PV modules. (I've had PV modules on my own roof since 1980.) It's your money; invest it where you want. I'm just saying, if you have an extra $6,000 to invest to improve the energy efficiency of a new house, where should it go first? It should never be invested in a PV array -- there is just too much low-hanging fruit out there to invest in first.
Let's say that a state has $25 million in systems benefits charges it wants to invest in energy improvements. Where should it go -- a well-run low-income weatherization program, or PV subsidies? That's easy to answer -- low-income weatherization.

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Yes, and the answer to highway congestion is to build more traffic lanes.
Short-term thinking will often (always?) incur long-term costs.
Martin, do you have any numbers on the payback of a "well-run low-income weatherization program?"

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The NAHB is starting to panic about Green Building requirements becoming code mandated. The PVC window industry is already in a state of panic because ot the Green movement to ban all PVC products nationwide. From this morning's WDM (Window & Door Manufacturers) magazine's newsletter:

Homebuilders Call for Flexibility in Green Building

Energy efficiency is a major focus for homebuyers and homebuilders, but a one-size-fits-all green building standard is not the answer, the National Association of Homebuilders (NAHB) told a Senate panel last week. Speaking for the association, Alaska homebuilder Jack Hébert said, "Only flexible, locally-grown green building programs can adequately take local issues, architecture, weather and geographical differences into account."

The NAHB has issued Model Green Home Building Guidelines that allow builders to address the local environment and assess life-cycle costs based on local building codes and climate zones.

"Homebuilders look to PVC products to increase energy efficiency, whether in hot or cold climates," said Tim Burns, president of the Vinyl Institute.

For example, PVC figures prominently at the new Cold Climate Housing Research Center in Fairbanks, Alaska. Designed with daylighting in mind, the center uses robust Capitol Glass/Northerm commercial-rated vinyl (PVC) triple-glazed windows.

Hébert, who is president and CEO of the center, uses Northerm vinyl windows on all the homes built by his own company, Hebert Homes/Taiga Woodcraft. According to data from the Department of Energy, homeowners can save between $125 and $340 per year by replacing single-pane windows with ENERGY STAR® vinyl windows.

In Hawaii on the other hand, energy efficiency is hardly a matter of capturing heat and light and guarding against cold. Major energy bills enacted in 2006 included promulgating a tropical energy efficiency building code. A new residential energy code, geared to retaining the coolness within air-conditioned homes, requires R-19 or equivalent roofs. The code allows several paths to achieve this, including cool roofs. Burns pointed out that PVC is a major material for light, reflective cool roofs, which not only lower the temperature within the building, but also reduce the "urban heat island" effect, thereby reducing smog.

The Greens are saying that Green building should contain no PVC or CPVC products:

TIME FOR ACTION ON PVC AND DIOXIN

According to USEPA's dioxin reassessment, dioxin is extraordinarily toxic, persistent, and bioaccumulative. Dioxin is now distributed globally in the environment, food chain, and human tissues, and EPA has found that current "background" levels of dioxin are already at or near the range at which health effects are known to occur. These findings provide added weight to recommendations such as the International Joint Commission call for a phaseout of chlorine use in products such as PVC in order to eliminate on a rapid timetable the generation and release of dioxin into the environment.

PVC is the largest single contributor to the national dioxin burden. For the protection of public health and the environment, a PVC phase-out must be a priority in the national dioxin prevention program. Important first steps include:

* Prohibition of the oxychlorination process for the production of EDC and other chemicals;
* Prohibition of new facilities or capacity expansions for the production of EDC/VCM and PVC;
* Modification of existing permits for EDC/VCM plants to bring generation and releases of dioxin to zero;
* Classification of relevant wastes from EDC/VCM production as dioxin-listed and PCB-containing wastes, subject to all appropriate regulatory requirements that have been revised to reflect the inadequacies and limitations of incineration as a treatment technology;
* Prohibition of incineration of chlorine-rich wastes and/or wastes from EDC/VCM production that contain dioxin and PCBs;
* Rapid phase-out of PVC uses associated with the largest dioxin releases, including short-life PVC uses (packaging and disposable products sent to incinerators or otherwise burned), uses in areas susceptible to fire (construction, appliances and automobiles), and products recycled in smelters (cables and cars); and
* A longer-term phase-out of other uses of PVC, with priorities established according to environmental impact and the availability of alternatives.

Because the ultimate phase-out of PVC will have economic impacts in the communities where manufacturing facilities are located, transition planning processes must be an integral component of any phase-out plan. This process must be guided by participation from labor, community and other stakeholders and should seek to minimize the economic effects of the transition and insure that costs and benefits are equitably

distributed. For instance, the Oil, Chemical, and Atomic Workers Union has proposed a tax on chlorine and related chemicals; the revenue would be used to encourage reinvestment in affected communities and to provide income protection, continued health care, and meaningful opportunities for higher education and reemployment for workers and their families.*